I'm in need to apply a validation on a double value which needs to match with PI. I'm thinking to use a #Pattern(regex="3.14159265359"). Is it the best way I can apply such a constraint using Hibernate Validation Constraints?
Thanks
#Pattern is only defined for string type (CharSequence really). If your data type is a double you cannot use it, unless you write a custom ConstraintValidator. You could use DecimalMin in combination with DecimalMax potentially allowing for some imprecision. Alternatively, you could write your own constraint #Pi which for example allows to specify a delta. #Pi is probably the best solution, provided you really need this validation.
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For the Dymos problems I work with, I have code that adds states, controls, etc. in bulk and then use the set_XXX_options() method to specify specific parameter values (e.g. opt=True). This is easy for Dymos phases, because each phase has a add_XXX() method and an associated set_XXX_options() method. However, the trajectory.add_parameter() method does an associated trajectory.set_parameter_options() method.
Is there a reason the set_parameter_options() method is not available for trajectory objects? Can it be added as a method?
This is a good point and there's no reason we can't add this method, and we should for API consistency.
In the mean time, you can access the parameter_options dictionary after add_parameter to change settings. For instance,
traj.add_parameter('foo', ...)
traj.parameter_options['foo']['opt'] = True
I'll add an issue to make this a part of the API.
I am trying to learn Servlet annotations and came across this snippet
#WebServlet(urlPatterns="/MyPattern", initParams={#WebInitParam(name="ccc", value="333")})
This makes sense to me. However, I don't understand why it is not like this
#WebServlet(urlPatterns="/MyPattern", initParams={(name="ccc", value="333"), (name="abc", value="1")})
So, the question is why we need to put #WebInitParam annotation when we already declared the attribute as initParams. It seems redundant to me, or am I missing something?
The alternative you suggest would not even compile.
When you look at the JLS, it states this:
It is a compile-time error if the return type of a method declared in
an annotation type is not one of the following: a primitive type,
String, Class, any parameterized invocation of Class, an enum type
(§8.9), an annotation type, or an array type (§10) whose element type
is one of the preceding types.
So in order to group name and value together, which represent the initialization parameter the only option is to use annotation (#WebInitParam in this case) with corresponding values set as its parameters.
As with most questions about language design choices we can only speculate here. I think some reasons for this are:
Keeping the language simple.
It is kind of redundant, but the syntax for annotations can be reused and does not require new language constructs. This makes it easier to parse and to read. Sure, It's longer, but it's also more explicit to write the annotation's name.
Don't restrict possible future language enhancements.
The proposed syntax would not work if annotations would support inheritance. I don't know if that's even a planned feature but it would not be possible to implement straightforward it if the type can be omitted.
In many cases an array of annotations seems like a workaround anyway. It can be avoided in Java 8, where you can add multiple annotations of the same type:
#WebServlet(urlPatterns="/MyPattern")
#WebInitParam(name="ccc", value="333")
#WebInitParam(name="abc", value="1")
(I don't know if the servlet api actually supports this yet though)
First of all i am very new to Symfony 2 and started to learn.
Is there any possibility for filter a value? Perhaps filter chains too?
I know this concept from Zend Framework 1 and 2.
E.g.:
i have a string "1A- N "
now i want to filter so that only numeric values pass; result "1"
Do i have to implement this on my own i Symfony?
I would like to do something like:
$text = '1A - N';
$numberFilter = new NumberFilter();
$filteredText = $numberFilter->filter($text);
//now in $text i find '1'
But for now i nowhere found something like this in Symfony what surprises me a lot. I thought it is a full stack framework and such function is so basic.
I found something like validators but they only say if a value e.g. contains only numbers or not. Or is the validation concept of symfony like that it does not only say if it is numeric or not but filter all other smybols out, too?
Depending on what you want precisely:
disallow user input not fulfilling certain rules
use validators in forms
use asserts in entities
chenge user input in case it's wrong
use viewransformers in forms
use event listeners in forms
use event listeners for doctrine
change data that already exists in the database
use filters in twig
create a command to execute from commandline
You can also try http://php.net/manual/ro/filter.filters.sanitize.php
I have built quite big apps with Symfony and never needed such a feature. Filters are mostly used in views anyway. Symfony comes with Twig, which has filters, that can be chained, and you can write your own filters. But if you need filters in the backend to do some background processing, you can accomplish it the way you suggested.
I suggest you write an interface and use a factory pattern, so you set a standard if you make many filters, so it will be easier to make the chaining work;)
After the answers and searching i got to the following conclusion.
There is no concept for this for now in Symphony 2.
You have to write it on your own.
I'd like to configure bean validation (JEE6) constraints via a properties file or database.
So for instance the Max value below would get pulled from the properties file or database.
Is this possible in ?
#Max(value = 1)
private int elvis;
Any suggestions on a possible approach.
It is not possible via standard Bean Validation. The default as per specification are annotations or as alternative XML.
In theory, Hibernate Validator has the (internal) concept of a MetaDataProvider and one could think of plugging in a DbMetaDataProvider. However, that would be quite some work and I am not sure that it would be worth the effort.
What is you use case anyways? Why don't you use XML?
You can write your own constraint and validator for that. The constraint’s argument could be some identifier of the validation parameters stored in database and the validator could query database for these parameters to validate a value according to them.
Some hints:
See this validator for an idea how to reuse existing validators from your “über validator”.
See this question and this answer for a hint how to inject bean to a validator.
Intro: I'm writing web interface with SQLAlchemy reflection that supports multiple databases. It turns out that authors of application defined postgresql with lowercase tables/columns, eg. job.jobstatus while sqlite has mixed case, eg Job.JobStatus. I'm using DeclarativeReflectedBase from examples to combine reflection and declarative style.
The issue: Configure SQLAlchemy to work with tables/columns case insensitive with reflection
I have done so far:
I have changed DeclarativeReflectedBase.prepare() method to pass quote=False into Table.__init__
What is left to be solved:
relationship definitions still has to obey case when configuring joins, like primaryjoin="Job.JobStatus==Status.JobStatus".
configure __tablename__ based on engine type
The question: Are my assumptions correct or is there more straightforward way? Maybe I could tell reflection to reflect everything lowercase and all problems are gone.
you'd probably want to look into defining a ".key" on each Column that's in lower case, that way you can refer to columns as lower case within application code. You should use the column_reflect event (See http://docs.sqlalchemy.org/en/latest/core/events.html#schema-events) to define this key as a lower case version of the .name.
then, when you reflect the table, I'd just do something like this:
def reflect_table(name, engine):
if engine.dialect.name == 'postgresql':
name = name.lower()
return Table(name, autoload=True, autoload_with=engine)
my_table = reflect_table("MyTable", engine)
I think that might cover it.